1. Field of the Invention
The invention relates to a method for joining a metallic member and a resin member to each other, a manufacturing method for a cooler, and a cooler.
2. Description of Related Art
In recent years, various types of industrial products have been developed, in which a metallic member with excellent thermal conductivity, electric conductivity, extensibility, and so on, and a lightweight and inexpensive resin member are joined to each other. As a matter of course, in such industrial products, reliability of a junction between a metallic member and a resin member, which are made of different materials, becomes an issue.
A joining method is disclosed in Japanese Patent Application Publication No. 2010-173274 (JP 2010-173274 A), in which, in order to rigidly adhere a metallic member and a resin member to each other, a polar functional group is added onto a surface of the metallic member, and an adhesive modifier containing an adhesive functional group that mutually interacts with the above-mentioned polar functional group is combined with a resin that structures the resin member.
The inventor has found the following problem. In the joining method disclosed in JP 2010-173274 A, in order to promote a reaction between the polar functional group added onto the surface of the metallic member and the adhesive functional group contained in the resin, it is necessary to bring the metallic member and the resin member into contact with each other for a given period of time after heating the metallic member and the resin member to resin melting temperature or higher. Therefore, there is a problem that, when the metallic member and the resin member are kept being pressed to each other while joining, the resin protruding from the junction (or flash) is increased. Meanwhile, if the metallic member and the resin member are not pressed to each other in order to suppress generation of flash in the junction, there is a problem that air bubbles generated due to melting of the resin remain inside the resin member in the junction, thereby causing degradation of strength.